Journal Issue: Low Birth Weight Volume 5 Number 1 Spring 1995
What should and could be done to reduce the problem of low birth weight and infant mortality in the United States? Are there areas of current research and practice that should receive less attention? Are there areas that need to be given higher priority? In the following section, several important steps that could be taken to reduce the number of low birth weight and preterm births in the United States are discussed.
Preventing Low Birth Weight and Preterm Births
Smoking During Pregnancy
The most obvious way to decrease rates of low birth weight and preterm birth is to stop cigarette smoking during pregnancy. Cigarette smoking during pregnancy causes close to one-fifth of all low birth weight births and is the single most important known cause of low birth weight.
• Focus additional resources on stopping cigarette smoking during pregnancy. Because of the highly addictive nature of nicotine, preventing young women from starting to smoke cigarettes should be a high priority. This will require a multilevel commitment from society, schools, medical care systems, insurers, families, and individuals.
Because cigarette smoking is not likely to be totally abandoned in our society, additional resources should be applied toward helping women quit smoking during pregnancy. These resources need to be allocated to two related areas: developing more effective ways to help pregnant women quit smoking and determining where and how best to implement these interventions. Because nicotine is such an addictive drug, the success rates of most smoking cessation intervention programs are low. Only 9% to 27% of women who participate in these programs are able to quit smoking during pregnancy, and an additional 17% to 28% reduce the amount smoked (see the article by Alexander and Korenbrot). Moreover, many women who do quit during pregnancy relapse quickly after the birth of the baby.18 The nicotine patch or gum, one of the more effective ways to help smokers quit, is not recommended for use during pregnancy.18 Thus, to make a measurable impact on reducing rates of low birth weight, new and innovative ways to help pregnant women quit smoking are urgently needed.
Developing ways to integrate smoking cessation interventions into prenatal care seems a logical first step because most pregnant women have contact with health care providers during this period. However simple this appears, it will not be easy, as very few health care providers are prepared to offer such specialized care. Training in smoking cessation should be an integral part of the education of physicians and other reproductive health workers. The effectiveness of utilizing other, nonmedical providers to institute smoking cessation programs for pregnant women within the prenatal care setting and elsewhere should be evaluated. These smoking cessation services ideally should be closely linked with prenatal care but need not rely on medical care providers to administer them.
• Making sure smoking cessation programs are part of every health insurance package would provide the economic means to pay for these smoking cessation activities.Studies of the cost-effectiveness of smoking cessation interventions in pregnancy show that relatively small investments in these interventions can have benefits.19 Costs for smoking cessation interventions may easily be recovered by reductions in medical costs of caring for low birth weight infants19 and in the need for chronic care for both mother and child in later life.Prenatal Care
• Recognize that for all the valuable contributions prenatal care makes to maternal and child health, in its present form it does little to prevent low birth weight or preterm birth. From a medical perspective, the purpose of prenatal care is to diagnose and treat a variety of medical conditions that affect the mother and fetus. The medical conditions uncovered during prenatal care affect only a relatively small proportion of all pregnant women and many of these conditions, while important, do not cause low birth weight. However, this should not be interpreted to mean that prenatal care has no value. Prenatal care provides a number of benefits which do not relate directly to the prevention of low birth weight. These include prevention of maternal deaths; education regarding pregnancy, labor and delivery and newborn care; the potential for linking disadvantaged women to important social services; and an increased likelihood that newborns will receive needed preventive care. These and other positive outcomes must be considered in any complete evaluation of prenatal care. However, even the best prenatal care alone cannot be expected to solve the dual problems of low birth weight and preterm birth.
• Concentrate resources on improving the content and structure of prenatal and obstetric care. Prenatal care is an important well-used set of services; not enough, however, is known about the effectiveness of the various components of that care. The content of prenatal care visits is highly variable, and little is known about how well that content corresponds to the needs of pregnant women. Members of a national panel agree that, at a minimum, quality prenatal care should include early and continuing risk assessment, health promotion, and medical and psychosocial interventions and follow-up. The content of prenatal care visits should vary depending on the risk status of the pregnant woman and her fetus.9 It is thought that quality care could be provided in fewer prenatal visits, and the schedule of visits should be rearranged so that more visits occur early in the pregnancy and fewer visits occur in the third trimester. The timing of visits should be flexible, and the various aspects of care should be integrated to minimize the number of visits by the woman and the amount of inconvenience to her.9 If prenatal care is also to be used as a vehicle for the prevention of low birth weight and preterm birth, care as practiced today needs to be wholly reexamined and restructured to emphasize those elements that can realistically be expected to have a positive impact. In addition, access to prenatal care, while good, is not universal. Improvements in the availability and accessibility of prenatal care are needed, particularly for women who are impoverished or are from disadvantaged groups.9
• Develop a concerted program of women's health that includes prepregnancy counseling. Women's health programs that include prepregnancy care should be developed to educate women who are considering pregnancy about things they should do before becoming pregnant. For example, prepregnancy care has the potential to prevent the occurrence of a serious but rare birth defect, spina bifida, which sometimes is caused by extreme dietary deficiencies in folic acid. This is possible only if women are aware of the risk, are screened for diets deficient in folic acid, and if found deficient, are encouraged to take appropriate dietary supplements to assure that they have an adequate intake of folic acid. This intervention will work only if supplements are taken around the time of conception and in early pregnancy. In addition, assuring that women are immune to rubella, controlling the effects of diabetes, and treating sexually transmitted diseases should be done before pregnancy. Because conventional prenatal care is initiated several months after conception, it is not designed to address these and other events that occur before or very early in pregnancy.
• Encourage obstetricians to make wider and more frequent use of prenatal corticosteroid treatment. Each year a sizable number of women have preterm births, and most could benefit from prenatal corticosteroid treatment. While corticosteroid treatment does not actually prevent preterm birth, it has the potential to reduce serious lung disease and brain damage, and to improve the chances for survival among preterm infants.20 Despite very convincing evidence supporting the effectiveness of this treatment, it is currently being offered to only a small minority of the pregnant women who should be receiving it. The infrequent use of such an important therapy brings into question the ability of the medical profession to reach individual physicians with the most current, effective therapies.
Two important areas of research—basic science research and medical and epidemiologic research—will provide the information needed to understand the process of labor and delivery and the causes of low birth weight and preterm birth and will make it possible to prevent these adverse outcomes. The problem of low birth weight is a serious one and has an important economic component. According to Lewit, Baker, Corman, and Shiono, the annual estimated costs of low birth weight ($6 billion adjusted to 1988 dollars) are more than two times that of AIDS among persons of all ages ($2.4 billion adjusted to 1988 dollars). Yet, low birth weight receives much less attention and fewer research dollars than AIDS.
• Basic Science Research
• Focus additional resources on finding out what triggers preterm labor. Being born too soon is the main cause of low birth weight and infant mortality in the United States. Finding out what causes preterm labor and the factors that trigger this process will provide the basic knowledge needed to develop and test new ways to prevent preterm birth. At present, there are few clues to guide the search for causes of preterm labor. Nathanielsz notes in his article that, in normal pregnancies, the fetus determines the duration of the pregnancy, and this duration is linked very closely to the maturation of the fetus's vital organs. The initiation of labor also appears to be controlled by the fetus. Specific hormonal changes in the fetus cause the mother's body to produce the signals that initiate labor. Determining the mechanisms for even one of the many critical points in this complex process of labor may make it possible to develop preventive therapies and drugs that could interrupt the process of preterm labor.
The observations by Nathanielsz that the birthing process is a complex multifactorial system of interconnected physiological mechanisms and that preparatory changes occur in the fetus and mother several weeks before labor begins suggest the need to concentrate on the study of preterm labor early in the pregnancy. The effect of infectious agents on the placenta and other parts of the reproductive system also needs to be investigated. Initial studies have shown a connection between infections and preterm labor, but how and if these infections actually initiate the process of labor in humans is not known. Efforts to find drugs that will suppress or delay preterm labor are ongoing. Currently, drugs to prevent preterm labor are only effective in delaying birth for one to two days; however, several promising new therapies are being tested. Moreover, because the fetus plays a key role in determining the initiation of labor, research on the initiation of labor in humans needs to take a more intensive look at the fetus, particularly the fetal brain and fetal development, to understand the labor process.
• Epidemiologic and Medical Research
• Focus resources on discovering the causes of the differences in the rates of preterm birth and low birth weight among racial and ethnic groups. One of the most important clues about the cause of preterm birth and low birth weight comes from the observation that there are large racial and ethnic group differences in these outcomes. African-American infants are twice as likely as infants of nearly all other ethnic/racial groups in America to be born low birth weight and to be born preterm. Discovering the reasons for these racial differences may provide clues to the causes of preterm birth and low birth weight.
Research in the past decade has not uncovered the reasons for these large ethnic group differences in low birth weight.21-24 This work has examined the effects of a number of behavioral, socioeconomic, or medical risk factors such as smoking, drug use, inadequate use of medical care, poor health conditions, infections, poverty, employment, physical exertion, poor nutrition, stress, and lack of social support. Interestingly, Hispanic and Asian-American women who have similar levels of poverty to African Americans have rates of low birth weight and infant mortality comparable to white infants. This provides some evidence that poverty may not be the sole reason for the high rates of infant mortality among African Americans.21 While it is valuable to know what does not cause the racial group differences in low birth weight and preterm birth, more emphasis needs to be placed on studying the basic biological differences between the racial groups which may be responsible for these disparities.
Another important observation is that the average birth weights of African-American and Asian-American infants are approximately one-half pound less than those of white infants.21 However, in spite of their lower average birth weights, the rate of infant mortality for Asian-American infants is the same as or lower than the rate for white infants.25 In contrast, African-American infants have average birth weights that are similar to those of Asian-American infants, yet African-American infants are twice as likely to die as either white or Asian-American infants.25 These observations illustrate the apparently normal variations in the birth weight distribution, with two groups—whites and Asian Americans—having very different birth weight distributions, yet similar rates of low birth weight and infant death. This leads to the conclusion that merely having small babies is not the entire problem, but that as-yet unknown factors predispose African Americans to having very small preterm infants who are more likely to die. However, simple measures such as birth weight and gestational age are not enough to explain important ethnic group differences in outcomes.
One area of needed research is the potential biological or genetic differences between the racial and ethnic groups which distinguishes between the low birth weight that occurs as a result of normal variability in infant size and the low birth weight that occurs as a result of environmental and/or biological injury. It appears likely that a disproportionate number of African-American low birth weight births occur as a result of environmental and/or biological injuries, and not as a result of normal variations in infant size. Normal variability in size would not be responsible for the doubled rate of infant mortality, whereas, an increase in the number of low birth weight infants born as a result of these injuries could result in increased rates of infant mortality. However, the degree to which the observed differences in low birth weight and early delivery among the racial or ethnic groups reflects normal biological variation is currently unknown. If social and economic reasons are not the dominant cause of these racial differences, then these observations cry out for biological explanations.
• Simultaneously emphasize the role of socioeconomic, environmental, and lifestyle factors along with genetic and physiological factors in future research. What makes the African-American fetus more likely and the white or Asian-American fetus less likely to initiate preterm labor? The answers to these questions will probably be multifaceted. At the root of the question is the complex interplay of individual susceptibility and the multitude of potential environmental stimuli. One way to begin to answer this question is to focus more closely on pregnancy and labor among African Americans and to look for physiological differences in these processes which might provide clues about the racial disparities in infant mortality. A clear understanding of why babies are born too early and sick may make it possible to eliminate these ethnic differences in infant mortality.
Caring for Low Birth Weight and Preterm Infants
• Develop ways to improve the quality of medical care by assuring that proven, effective technologies are used and disseminated, and that ineffective technologies are abandoned. The tremendous advances in neonatal intensive care technologies over the past 20 years carry a high price tag. Low birth weight infants make up 7% of all infants, but 35% of the dollars spent on health care for infants goes toward their care, with nearly half of these dollars going toward the care of the tiniest infants. A disturbing majority of specific technologies, procedures, and therapies included as part of this intensive care have never been adequately tested for their effectiveness.
Because of the high cost and experimental nature of many neonatal intensive care technologies and therapies, it is crucial that the evaluation of these technologies and therapies receive particular attention. It is especially important to study the subset of extremely tiny infants who are now surviving as a result of this intensive care. Tyson makes the point that many, if not most, of the interventions practiced as part of neonatal intensive care have not been formally evaluated in clinical trials. Clinical trials should be set up on a national basis which would allow the families of these tiny newborns the opportunity to join ongoing studies. Perhaps study of the efficacy of neonatal intensive care could be modeled after the Children's Cancer Group and the Pediatric Oncology Group, which enroll the vast majority of children diagnosed with cancer into randomized trials that test the efficacy of different forms of treatment for these rare conditions. In this way, the care of these infants could be studied, and the valuable information about their care and treatment is used to improve future care. Information about the long-term consequences of these intensive care procedures should also be combined with data on the cost of caring for these infants. Promoting only those technologies that are proven to be effective and abandoning those that are ineffective will conserve health care dollars and keep infants from receiving unnecessary, often invasive procedures.
Clinical evaluation science is a new and growing field which could provide the infrastructure to help improve the quality of medical care for women and children. Techniques such as meta-analysis, in which evidence from several clinical trials is objectively synthesized, are being used to develop practice guidelines which provide clinicians with current information about how to care for particular illnesses. In addition to helping physicians decide how to treat particular conditions, clinical evaluation science takes the next very important step and concentrates on developing more effective ways to help physicians actually change the way they practice medicine. The goal of clinical evaluation science is to rely on data-driven solutions rather than on chance occurrences to direct the practice of medicine. To make this form of quality improvement work requires a team approach among health care providers, insurers, and consumers.
• Define what care, if any, should be given to the most immature, malformed, or sick infants. While future research will further define the effectiveness of the specific technologies used as part of neonatal intensive care, resources need to be focused on how to decide which infants should be administered intensive care and which infants should be treated with "comfort care." Without intensive care, most of the very small, sick infants will die soon after birth. However, while intensive care may have the power to save some of these infants, it also has the power to prolong the pain, the suffering, and the process of dying for many others. Federal child abuse laws require the use of intensive care for all critically ill infants, except when the care is futile or inhumane. However, the interpretation and application of this law has been inconsistent because the law as written provides very little practical guidance for clinicians and families on how to determine if care is futile or inhumane. Practical guidelines are needed to help families and physicians make decisions regarding the care of critically ill infants whose chances for survival are poor. These guidelines should assure that the interests of the infant, the parents, health care providers, and society are represented without creating a bureaucracy that interferes with the patient-physician relationship.
• Increase support for programs to define new and better ways to meet the wants and needs of distraught parents who are likely to be faced with the birth of a critically ill baby. Strategies should be developed to help assure that parents are informed about the condition of their infant, the treatment options, and the future prospects for their child's development. Ideally, discussions should occur between the parents and health care providers before the birth of an affected child so that parents are able to make these very difficult decisions outside a crisis situation. The potential for creating undue concern among parents must be balanced with the desirability of having them be fully informed about the numerous but extremely rare potential adverse outcomes. The role of parents, medical care providers, researchers, policymakers, and society in the process of making crucial decisions about the care of these extremely fragile and tiny infants also needs to be clarified.
• Maintain a constant and ongoing commitment to children who are born low birth weight or preterm. Commitment to these children should not stop when they go home from the hospital. Most low birth weight and preterm infants grow up to be healthy adults. However, some low birth weight infants are not so lucky. These infants—particularly the extremely low birth weight infants and their families—must learn to cope with challenging lifelong disabilities. Data show that the adverse health and developmental effects of being born low birth weight can often be reversed. Federal laws also mandate services for disabled children, including those with disabilities resulting from being born low birth weight. Additional resources should be provided to assure that these disabled children receive the health, educational, psychological, and social services they need.
In the current wave of deregionalization, neonatal intensive care for critically ill newborns appears to be moving from centralized university-based settings to more diffuse suburban settings. As part of regionalization of care, multiservice follow-up clinics were also strategically placed at university-based hospitals which had the capacity to serve a large regionalized population and staff these centers with the necessary highly trained medical and developmental specialists. These multiservice clinics have made it possible for families with children who have serious medical and developmental problems to receive high-quality coordinated care in an efficient way. Whether diffusion of intensive care will enhance access to existing regionalized centers or inadvertently introduce new barriers for families of very ill children who need follow-up services after they leave the hospital is unclear. Local action may be required to assure that needed services are available to these children.